5. Reproduction of Plants

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1 5. Reproduction of Plants
How do plants reproduce? Plant’s life cycle Grows taller Seed種子 Germinates 發芽 Develops stem, leaves, roots Develops Flower 開花 Produces a fruit 結出果實 Flower withers 凋謝

2 How do plants reproduce?
What stages has the tomato experienced? It grows from the seed. It has gone through the stages of : Germination Growth Flowering Fruiting After the seeds __________, the roots, stems and leaves develop. Some plants have flowers and produce _____________. 發芽 germinate fruits 果實

3 The function of seeds Seeds How do tomatoes reproduce? Seeds
Tomatoes produce flowers and fruits. The seeds in the fruits can produce new plants.

4 seeds How do plants reproduce?
Fruits contain ______________. They can produce new plants. seeds

5 Stamen雄蕊 Pistil 雌蕊 Calyx花萼 Corolla 花冠
How do flowers relate to plant’s reproduction? Structure of a flower Stamen雄蕊 Pistil 雌蕊 Calyx花萼 Corolla 花冠 Corolla Pistil 雌蕊 Attracts insects for pollination. 傳播花粉 Receives pollen 花粉 Stamen 雄蕊 Calyx花萼 Produces pollen Protects the bud 未開的花

6 How do insects help pollination?
When an insect collects nectar花蜜, pollen from the stamen is stuck onto its body. When the insect flies to another flower, it brings the pollen to the pistil of that flower. Pollen is stuck onto the insect 昆蟲沾上雄蕊的花粉 Pollen is brought to the pistil of another flower.

7 How do insects help pollination?
What are the features of the insect pollinated flowers? 蟲媒花 Most of the flowers are colourful and have nectar and big petals to attracts insects.

8 How do these plants spread their pollen?
By wind Corn 玉米 The wind blows the stamen of the corn and the pollen will land on the pistil of another plant by wind.

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10 Process of fruiting How is fruit developed after pollination?
After the pistil has received the pollen, the ovary子房grows and develops into fruit. Ovary 子房 Seeds種子 Flower withers The ovary grows發育 Flowering plants are pollinated by insects or by wind. When pistil receives pollen, the ovary develops into _______________. The ovary develops into fruit fruits果實

11 Seeds are protected by the fleshy part of fruits.
How does a seed develop into a new plant? Cut some fruits and observe the seeds inside. Why are the seeds stored inside the fruits? Seeds are protected by the fleshy part of fruits.

12 How does a seed develop into a new plant?
Soak a broad bean for two days. Cut it and observe the following parts. Seed coat種皮 Cotyledon子葉 Embryo 胚 Plumule胚芽 Radicle胚根

13 Write the names of the different parts of a seed according
to their functions. Seed coat : Protects the seed 保護種子 _____________: provides nutrients for germination. 萌芽 Cotyledon 子葉

14 Write the names of the different parts of a seed according
to their functions. ___________: grows into stems and leaves莖和葉 __________ : grows into roots 根 Plumule胚芽 Radicle 胚根 A seed consists of seed coat and embryo. The ______________ protects the seed and the _______________ develops into a new plant. seed coat 種皮 embryo 胚

15 Seed dispersal 種子散播 Why do plants need to disperse their seeds?
Plants need sunlight, water, air and nutrients to grow. Water and nutrients If their seeds are not dispersed, the new plants will not be able to get enough sunlight, water, air and nutrients in an area crowded with plants.

16 How do these plants dispersed their seeds?
Coconut By water Hairy bur-marigold鬼針草 Carried by animal Dandelion 蒲公英 By wind

17 How do these plants dispersed their seeds?
銀合歡 Pods of white popinac Tangerine 桔 By self-explosion Eaten by animals

18 What characteristics do these seeds / fruits have?
The fruits have hooks or spines 長有倒鈎的小刺 Air-filled fruits Seeds are light and have feathered structured 翅膀狀薄膜 The fruits will burst open裂開while they ripen成熟 The fruits are juicy 多汁 Plants disperse their seeds by ____________, _____________, ______________, and self-explosion. water wind animals

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24 怎樣用人工方法繁殖植物？ 有些植物如萬年青、秋海棠等，我們可以利用它們的某部分種出新的植物。你曾經用以下方法繁殖植物嗎？ 植物名稱：萬年青
繁殖方法：用莖來繁殖 (插枝法) (1) 剪出一段至少有兩節的莖。 (2) 把莖插入泥土中。 (3) 莖上有節的地方長出根和葉。

25 怎樣用人工方法繁殖植物？ 有些植物如萬年青、秋海棠等，我們可以利用它們的某部分種出新的植物。你曾經用以下方法繁殖植物嗎？ 植物名稱：秋海棠
繁殖方法：用葉來繁殖 (葉插法) (1) 把葉片沿著葉脈切開。 (2)將葉片的切口朝下插入泥土中。 (3)葉片切口處會生根發芽，長出新植物。

26 怎樣用人工方法繁殖植物？ 有些植物我們可以採用人工的方法繁殖，例如 、 等。 插枝法 葉插法